Cobble Mountain
Hydro power plant in Hampden County, Massachusetts. 33 MW of nameplate capacity across 3 generators, operated by City of Holyoke Gas and Elec Dept - (MA).
Also known as EIA plant 1630
Analyst: free account, 1 question a day.
Key facts
- Capacity
- 33 MWNameplate
- Generators
- 3 operatingEIA-860M, August 2026
- Operating since
- January 1930First generator online
- Operator
- City of Holyoke Gas and Elec Dept - (MA)EIA operator ID 8776
- Grid
- ISO-NEBalancing authority ISNE
- Price nodes
- 1 ISONE nodeResource nodes with prices
- Location
- Hampden County, MA42.1171, −72.8647
- EIA plant ID
- 1630EIA plant page
Data as of EIA-860M August 2026 (published 2026-09-24). Capacity is nameplate, not live output.
How much power Cobble Mountain produces
Free · EIA-923Net generation, 2025
7.06 GWh
7,061 MWh, final
Capacity factor, 2025
2.4%
2024: 2.7%
January to July 2026
Not reported
Provisional. 0 of 7 months reported
Range, 2015 to 2025
7.1–29.2
GWh a year. Low 2025, high 2018
| Year | Net generation, MWh | Capacity factor | Months reported |
|---|---|---|---|
| 2000 | 26,638 | Not reported | 12 of 12 |
| 2001 | 30,888 | Not reported | 12 of 12 |
| 2002 | 11,680 | Not reported | 12 of 12 |
| 2003 | 25,055 | Not reported | 12 of 12 |
| 2004 | 21,073 | Not reported | 12 of 12 |
| 2005 | 29,185 | Not reported | 12 of 12 |
| 2006 | 50,824 | Not reported | 12 of 12 |
| 2007 | 22,853 | Not reported | 12 of 12 |
| 2008 | 25,794 | Not reported | 12 of 12 |
| 2009 | 24,789 | Not reported | 12 of 12 |
| 2010 | 18,809 | 6.5% | 12 of 12 |
| 2011 | 34,732 | 12.0% | 12 of 12 |
| 2012 | 14,524 | 5.0% | 12 of 12 |
| 2013 | 21,770 | 7.5% | 12 of 12 |
| 2014 | 19,131 | 6.6% | 12 of 12 |
| 2015 | 18,696 | 6.5% | 12 of 12 |
| 2016 | 11,527 | 4.0% | 12 of 12 |
| 2017 | 10,651 | 3.7% | 12 of 12 |
| 2018 | 29,158 | 10.1% | 12 of 12 |
| 2019 | 21,064 | 7.3% | 12 of 12 |
| 2020 | 12,107 | 4.2% | 12 of 12 |
| 2021 | 20,845 | 7.2% | 12 of 12 |
| 2022 | 7,263 | 2.5% | 12 of 12 |
| 2023 | 10,531 | 3.6% | 12 of 12 |
| 2024 | 7,818 | 2.7% | 12 of 12 |
| 2025 | 7,061 | 2.4% | 12 of 12 |
| 2026 (provisional, partial year) | Not reported | Not reported | 0 of 7 |
* 2026 covers January to July and is provisional. Capacity factor is net generation divided by nameplate capacity times the hours of each reported month.
Power prices and basis
Free account · ISONEEmissions
Free · EPA CAMPDNo EPA emissions units are linked to this plant.
Water use
Free · EIA-923 cooling, USGSNo EIA cooling-water record for this plant in 2024. Plants without steam cooling, such as wind, solar and batteries, do not report cooling water.
Generators
Free · EIA-860M| Generator | Technology | Nameplate MW | Online since |
|---|---|---|---|
| 1 | Conventional Hydroelectric | 13.0 | January 1930 |
| 2 | Conventional Hydroelectric | 7.0 | January 1930 |
| 3 | Conventional Hydroelectric | 13.0 | January 1930 |
Ownership and offtake
ProOwnership and offtake are part of Pro
Owners and their shares, parent companies, and power purchase agreements with their buyers. EIA-860M lists City of Holyoke Gas and Elec Dept - (MA) as the operator, which is not always the owner.
Modeled data
ProPro adds modeled values for this plant. Everything above stays free.
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Power plants near Cobble Mountain
More plants operated by City of Holyoke Gas and Elec Dept - (MA)
Questions about Cobble Mountain
How much power does Cobble Mountain produce?
Cobble Mountain reported 7,061 MWh (7.06 GWh) of net generation in 2025, a 2.4% capacity factor on 33 MW of nameplate capacity.
Where is Cobble Mountain?
Cobble Mountain is in Hampden County, Massachusetts, at 42.1171, −72.8647. It is in the ISO New England Inc. balancing area (ISNE).
Who operates Cobble Mountain?
EIA-860M for August 2026 lists City of Holyoke Gas and Elec Dept - (MA) as the operator (EIA operator ID 8776). The operator is not always the owner.
When did Cobble Mountain start operating?
Its first generator began operating in January 1930, according to EIA-860M.
Does InfraMap have power prices for Cobble Mountain?
Yes. InfraMap has ISONE day-ahead and real-time prices at 1 price node linked to Cobble Mountain, with the hub price and node-to-hub basis. Prices are free with an InfraMap account; pricing node names are part of InfraMap Pro.
Sources
- EIA-860 2025 (final) and EIA-860M August 2026: plant, generators, capacity, operator and location
- EIA-923 monthly net generation, 2000 to July 2026 (2026 provisional)
- ISONE day-ahead and real-time prices; node and hub assignments as of 2026-10-05
Page updated 2026-10-04 from the InfraMap data build. Methodology · Data sources · EIA plant page